Simple Calculator

So this is something I made out of everything I've learned sofar.
I post it here so I can get pointers on what to improve on.

Code:

---

#include <iostream>

using namespace std;


void add(float x){
    cout << "Result: " << x << endl;
};
void sub(float x){
    cout << "Result: " << x << endl;
};
void mul(float x){
    cout << "Result: " << x << endl;
};
void div(float x){
    cout << "Result: " << x << endl;
};


int main()
{
    float a;
    float b;
    int c;


    cout << "Loke302 Simple Calculator!\n" << endl;
    cout << "Enter a number: ";
    cin >> a;
    cout << "Enter a number: ";
    cin >> b;
    cout << "[1] To Add\n[2] To Subtract\n[3] To Multiply\n[4] To Divide" << endl;
    cin >> c;


    if (c == 1) {add(a + b);
    return 0;
    }
    else if (c == 2) {sub(a - b);
    return 0;
    }
    else if (c == 3) {mul(a * b);
    return 0;
    }
    else if (c == 4) {div(a / b);
    return 0;
    }
    else if (c >= 5) {
        cout << "Option doesn't excist!" << endl;
        return 1;
    }
    else if (c <= 0) {
        cout << "Option doesn't excist!" << endl;
        return 1;
    }
}

---

Quote:

---

Originally Posted by Loke302

So this is something I made out of everything I've learned sofar.
I post it here so I can get pointers on what to improve on.

Code:

---

#include <iostream>

using namespace std;


void add(float x){
    cout << "Result: " << x << endl;
};
void sub(float x){
    cout << "Result: " << x << endl;
};
void mul(float x){
    cout << "Result: " << x << endl;
};
void div(float x){
    cout << "Result: " << x << endl;
};


int main()
{
    float a;
    float b;
    int c;


    cout << "Loke302 Simple Calculator!\n" << endl;
    cout << "Enter a number: ";
    cin >> a;
    cout << "Enter a number: ";
    cin >> b;
    cout << "[1] To Add\n[2] To Subtract\n[3] To Multiply\n[4] To Divide" << endl;
    cin >> c;


    if (c == 1) {add(a + b);}
    else if (c == 2) {sub(a - b);}
    else if (c == 3) {mul(a * b);}
    else if (c == 4) {div(a / b);}
    else if (c >= 5) {
        cout << "Option doesn't excist!";
    }
    else if (c <= 0) {
        cout << "Option doesn't excist!";
    }
    return 0;
}

---

---

You misunderstood what functions should be used for and how.
I'm showing you an example of how your add should ideally be.

Code:

---

double add(double x, double y)
{
    return (x+y);
}

---

You could show the result by:

Code:

---

cout<<"Result: "<<add(a,b);

---

Quote:

---

Originally Posted by manasij7479

You misunderstood what functions should be used for and how.
I'm showing you an example of how your add should ideally be.

Code:

---

double add(double x, double y)
{
    return (x+y);
}

---

You could show the result by:

Code:

---

cout<<"Result: "<<add(a,b);

---

---

Ok thanks I'll do that then :)

Last two if statements could be combined into one.
Break out as much code from the if statements as you can. For example, store the result in a variable somewhere and print the result AFTER the if statement.
Improving your indentation and code style would not be a bad thing either.

BTW, I didn't try to compile but I think the

Code:

---

using  namespace std;

---

is unnecessary in your current implementation.

Quote:

---

Originally Posted by walla

BTW, I didn't try to compile but I think the

Code:

---

using  namespace std;

---

is unnecessary in your current implementation.

---

No it isn't .... unless you want to do the same thing by different 'using' statements...or prefixing std at dozens of places.

Quote:

---

Originally Posted by manasij7479

No it isn't .... unless you want to do the same thing by different 'using' statements...or prefixing std at dozens of places.

---

He didn't use anything from std

Incorrect. cout and cin lies in the std namespace. So does endl.

Interesting..
thanks :D